Everything you do online can be seen by websites that use cookies to follow and sell your data. Now, a new app by Consumer Reports wants to make the market more transparent about which companies are collecting your personal data and what you can do to stop it.

The free app is called “Permission Slip.”

Just download and install it, create an account with your email address and phone number, and it will present you with a list of hundreds of companies.

Select one of the companies, and Consumer Reports will tell you what type of information it collects and your options for what you want to tell it to do.

You might have an account with one of the companies, but you can direct the app to send a message on your behalf requesting “Do Not Sell My Data” or to “Delete My Account,” and then move on to the next card, company or data broker.

“It’s extremely easy to use and it exists to help consumers exercise their rights to privacy and take back control of their personal data,” Ginny Fahs, director of product R&D at Consumer Reports’ Innovation Lab, told WTOP.

In the trillion-dollar commercial surveillance industry, browsers and even brick-and-mortar stores can track your every movement and sell that data to brokers — companies that are a largely unregulated part of the industry. That sold data then puts your personal information at risk of getting into the wrong hands or invading your privacy by pushing more products on you, according to Washington Consumers Checkbook.

Fahs led the team that developed the app.

“If it’s a company that you regularly do business with, then it could be to your advantage to have that company keep your data to not take action at all,” Fahs said. “A lot of states are starting to pass new privacy laws that give consumers a right to the data companies are collecting on us.”

WTOP’s Ciara Wells contributed to this report.